The Internet has emerged as a critical communication infrastructure, carrying traffic for a wide range of important scientific, business and consumer applications. Since Internet services are becoming ubiquitous, more and more businesses and consumers are relying on their Internet connections for both voice and data transport needs. Each component of the network is shared by a large number of businesses and consumers and needs to meet a variety of service quality expectations. Network service providers and enterprise network operators need to monitor the performance of the network and make changes in order to retain the high quality of service. For example, monitoring of delay for packets traversing the network provides information that could be used to determine where improvement in routing or capacity is needed.
The network management functions such as root-cause analysis rely on gathering network performance data. The network traffic and the network performance data arrive at a high data rate and require significant data reduction and analysis prior to being utilized for action. For example, network performance monitoring devices may measure TCP handshake times, roundtrip delay times, etc. and store the data for analysis and action. For example, the data might be used to search for virus signatures and trigger alarms and initiate mitigating steps. Data stream analysis techniques have been developed to make a single pass over the data, process the data stream, compute and store the results. The techniques have been used to automate and optimize the data stream processing for a single data stream by relying on a specific query from the user. Therefore, the performance monitoring devices may be monitoring traffic from a variety of sources such as different Internet Service Providers (ISP), different speeds and types of traffic, etc. However, the data stream processing requires a specific query for each stream from the network manager in a query language such as Standard Query Language (SQL).
Therefore, there is a need for a method that enables queries to be applied over multiple data streams.